Apparatus for casting dental fillings



J. A. HEIDBRINK APPARATUS FOR CASTING DENTAL FILLINGS 2 shezs-Sheat I Fiied Nov. 0, 1922 I/vvENToff F/'@ *2. JAY A. HE/DBR/NK.

BY QM/ A TTORNE Y6 A ril 8 1924. 1489 760 p J. A. HEIDBRINK APPARATUS FQR CASTING DENTAL FILLINGS File um. 2a. 1 22 w 2-$heets-5h6$t2 Patented Apr. 8, M24},

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JAY A. HEIDBRINK, OF MTNNEAPOLIS, MINNESOTA.

APPARATUS FOR CASTING DENTAL FILLINGS.

Application filed November 20, 1922.

To all whom it may concern:

Be it known that I, JAY A. Hnmnnrnx, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Apparatus for Casting Dental Fillings, of which the following is a specification.

My invention relates to apparatus for casting dental fillings. In making dental castings or inlays for use as dental fillings, it is customary to make a wax model or pattern having the shape of the tooth cavity which is to be filled. This model, after being removed from the tooth cavity, is surrounded with what is known as investment material with a sprue rod attached to the model and extending outwardly through the investment mate-rial, and after this material has become set, the wax model is burned out or melted so as to be absorbed by the surrounding investment material and the sprue rod having been previously removed, a matrix will be thus formed into which the molten metal or filling material is placed to form the inlay or casting which is to be placed in the tooth cavity. An object of the invention is to provide an apparatus for causing the molten metal to completely fill the matrix so that the casting will have the exact shape of the tooth cavity in which it is to be placed. An object in particular is to provide an apparatus of this character in which the molten material will be forced into the matrix by the air pressure exerted above the matrix and in which the air in the matrix will be removed and the material drawn into the matrix by suction exerted below the matrix.

The full object and advantages of my in vention will appear in connection with the I detailed description, and the novel features embodied in my inventive idea will be particularly pointed out in the claims.

In the drawings which illustrate the application of my invention, Fig. 1 is a view of the apparatus in vertical section on the line 1-1 of Fig. 2. Fig. 2 is a top plan view. Fig. 3 is a view partly in side elevation and partly in section. Fig. 4 is a view in horizontal section on the line 44 of Fig. 1. Fig. 5 is a view in vertical section on the line 55 ofFig. 4. Fig. 6 is a fragmentary view corresponding to Fig. 4 but showing a valve moved into a difierent position.

As shown in the accompanying drawings,-

Serial No. 602,148.

I provide a support consisting of a base 10 and a super-structure 11 carried thereby and preferably cast integrally therewith. The base 10 has a depression in its upper surface for receiving a flask M which contains the investment material I in which the cavity or matrix C has been formed to receive the casting material F. The investment material consists of plaster-ot-Paris or similar porous material commonly used for this purpose. The periphery of the flask rests upon a gasket 12 in the depression whereby a substantially air-tight joint is produced. The base below the position occupied by the flask is provided with an enlargement 14 through which passes a small perforation 16 extending down from the flask receiving depression and joining with an inclined and larger perforation l8. Arranged for cooperation with the. flask is a head member 20 carrying a gasket 22 adapted to engage the upper margin of the flask when the head member is depressed whereby an airtight joint is produced. The head member is secured to the lowerend of a tube 24 which at its upper end is provided with an annular piston 26 which fits slidably in a cylinder 28 carried by the superstructure 11. The piston 26 is normally held upwardly in the cylinder by a coiled spring 30 interposed between the piston and an annular flange 32 on the lower end of the cylinder. The

upper end of the cylinder 28 is provided with a screw plug 84 provided with a depending tube 36 which fits telescopically within the tube 24. The cylinder 28 near its upper end is provided with an inlet port 38 in communication with a passageway 40 in the superstructure. A rotary valve 42 controls the passageway 40, the outer end of the latter having a hose 44 attached thereto and connected with a suitable source of compressed air. The valve 42 contains a diametral opening 46 and a radial opening 48 at right angles to each other. When the valve occupies the position shown in Fig. 4, compressed air will be delivered to the upper part of the cylinder 28 and the head 20 will be depressed into the position shown in Fig. 3, and when the valve is turned through 90 into the position shown in Fig.- 6, the supply of compressed air will be shut OH and the compressed air in the cylinder will escape through a hole 50 in the wall of the casing in which the valve is mounted. The head 20 will then be restored to the I valve 7 position shown in Fig. 1 by the action of the spring 30. By referring to Fig. 3, it will be seen that when the piston 26 has been forced downwardly below an exit port 52 located intermediate the ends of the cyl inder compressed will pass through this latter port and through a tube into a vertical passageway 5.6 contained in an enlargement 58 carried by the superstructure above the base 10. A horizontal passage-- way 60 extends from the passageway and a tube 62 leads from the outer end passageway through a screw plug 6-1 fitting the lower end of a cylinder 66 carried by the superstructu-e. A partition 68 extending across the cylinder 66 is provided with a hole through which a stem 7 O extends the. stem being smaller than the hole so as to permit passage of compressed air. A plunger 72 is secured. to the upper end oi": this stem and valve 7% is secured to the lower end thereof. The valve 7 and the plunger 7 2 are normally held in the position shown in Fig. 1 by aspring 76 interposed between the valve and the plug 5% and by a spring 78 interposed between the plunger and a button 80 in the upper end of the cylinder chamber. A screw 82 passing thr' ugh a plug 8% in the upper end of the cylinder engages the button 80 and serves l l 4 w ,1 'gJ: to regiuate rile ioice icquiico. to nit the plunger against the tension of the spring 78. A pressure gauge 86 connected by a pipe 88 with the interior or the plunger portion of the cylinder indicates the pressure there in. When the pressure in the cylinder reaches a predetermined degree dependent upon "the setting of the screw 82 the plunger 72 will be liftedsuiiiciently to close the thereby preventing PZESSZlgQ or compressed air through the hole in the partition ln'incdiatcly above the partition 58 an enlargement 90 containing chamber l Lilli n ll 1:)

92 in cour unicaticn with the cylinder 3; Cor cted with the "lumber 92 1 g 94-1 hav 5 a passageway 96 to he valve chamber COD-Jillilllig a rotary val 019mb 98 which has a diametral. 5 100 and a radial. opening 102 at right auuies each other. assageway 10 1 in the upper portion of the valve casing leads to a chamber 106 which is connected by h the interior 01" the tube 1 n the head 20 permits compressed ss therethrougg h for forcing the casting metal into the mat ix. ll hole 112 in the valve casing 9 1 permits compressed. air to escape from the tube when-the valve 8 is turned to the left through 90 from the position shown in Fig. 1, thereby shutting off communication with the chamber 92; The lower end of the passageway 56 pre viously referred to opens into a chamber 114 which connects with a chamber 116 through a restricted opening 118 controlled by a neet having a head 122 by which i at urned for adjus ment. The

chamber 116 is connector. o a tune 121 with a passageway leading into the large per- 1 rati n previously re erred to. (on nected to the -mall peiioration 16 by a pipe 1 5 is 1 10 indicating the degree seed below the eXlb port n Ci v hen F er 28 ill pass through the tube 54: into the vertical passageway 56 where it c it assing thr ugh the tube or into the cylinder 66 from which it passes through the valve 98 the pipe 108, and the tubes 36 and 2a; ant. then through the hole 116 in the head 20 thereby forcing "the iaielted fil ing material into the matrix. ll hen he airpressure in the cylinder 66 become sulliciently high to lift the plunger 2 and he attached valve 7 1 and brings the atler into engagement with its valve seat. hen the supply of compressed air delivered 0 the c: linder 28 is cut off. The degreeoi pressure required to seat the valve may be ri ed by the screw 82 and the degree of: p o: re in the plunger chamber of the cyliiider may beobserved on the pressure pjaup'o Some of the compressed air dclivereo to the passageway 56 passes the needle valve 120 and escapes through the tube 152i and the p rforation 18 thereby suction downwardly through the ion 16 and exhausting air from the The degree or vacuum produced in ay 16 may be regulated by turn ilve 120 and may be obowever. it is intended that ordinarily i re above siuu'ion holds wi l be employed. When the matrix has been completely filled in this manner the valve 98 is turned through 90 from the position shown in Fig. 1, thereby shutting oil the Supply of compressed air to the tubes 36 and 24 and allowing the compressed air therein to escape through the hole 112 in the valve mpressed air delivered to weaves casing 94. The valve 42 is turned from the position shown in Fig. 4 to that shown in Fig. 6, thereby shutting off the supply of compressed air and permitting the compressed air above the piston 26 to escape so that the spring 30 lifts the plunger and the attached head 20 whereupon the device is ready for use with another matrix.

I claim:

1. Apparatus for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, means for supplying compressed air to the top of the matrix, and means whereby the escape of compressed air which has been used in operating the device will cause suction to be exerted on the bottom of the matrix.

2. Apparatus for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, a head normally held above the flask when thus positioned, a source of compressed air, means for causing compressed air from said source to depress said head into engagement with the flask, means whereby some of the compressed air which has been used to depress said head will apply pressure on the top of the matrix, and means whereby some of said compressed air will cause suction to be exerted on the bottom of the matrix.

3. Apparatus for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, a cylinder mounted so as to be above the flask when thus positioned, a piston in said cylinder, means for normally holding said piston in upward position, a tube depending from said piston, a head secured to the lower end of said tube, said cylinder having an upper port through which compressed air is admitted for depressing said piston and causing said head to engage the flask, means for supplying compressed air to said port, said cylinder having a lower port which is traversed by said piston when depressed, a second cylinder carried by said support. connections between said lower port and one end of said second cylinder, a valve in said second cylinder, -means for causing said inder mounted so as to be above the flask when thus positioned, a piston in said cylinder, means for normally holding said piston in upward position, a tube depending from said piston, a head secured to the lower end of said tube, said cylinder having an upper port through which compressed air plunger attached to the other end of said stem, means which normally holds said valve in open position and which permits said valve to be closed by the movement of said plunger caused by the compressed air when the latter reaches a predetermined pressure, and connections between the other end of said second cylinder and said tube for supplying compressed air through an opening in said head to the top of the matrix. 7

5. Apparatus for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, means for supplying compressed air to the top of the matrix, means for regulating the pressure of the compressed air which is thus applied, means for causing suction to be exerted on the bottom of the matrix, and means for regulating the suction which is thus exerted.

6. Apparatus for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, said support having a perforation which is underneath said flask when thus positioned and said support having a second perforation into which said first perforation extends at an angle, a head normally held above the flask, a source of compressed air, means for causing compressed air from said source to depress said head into engagement with the flask, means whereby someof the compressed air which has been used to depress said head will apply pressure on the topof the matrix, and means whereby some of said compressed air will be supplied to said second perforation whereby suction will be exerted on the bottom of the matrix through said first perforation.

7. Apparatus for casting dental fillings comprising a support adapted to receive a flask containing a matrix to be filled, said support having a perforation which is underneath said flask when thus positioned and said support having a second perforation into which said first perforation. extends at an angle, a head normally held above the flask, a source of compressed air, means for causing compressed air from said source to depress said head into engagement with the flask, a chambered member carried by said support, a passageway in said memher, means for conducting compressed air which has been used to depress said head into said passageway, connections leading from said passageway for causing some of the compressed air supplied thereto to apply pressure on the top of the matrix, connections leading from said passageway for conducting compressed air to said second perthe bottom of the matrix through said first 10 perforation, and a needle valve ror regulating the amount of compressed air supplied to said last mentioned connections.

In testimony whereof I hereunto efiix my signature.

JAY A. HEIDBRINK. 

